The present invention relates to a method for managing the air conditioning system of a hybrid automotive vehicle, either rechargeable or not, comprising an internal combustion engine and an alternative motor, and a vehicle employing this method.
To provide traction to the vehicle, hybrid vehicles contain in general two different energies which are kept in storage, one of which is reversible the other not, or typically electrical energy and a fuel.
The power connection to the storage device of reversible energy makes it possible either to use the energy contained in this device for applying traction force to the vehicle through the alternative motor, or to use the kinetic energy of the vehicle, in particular during a deceleration, in order to refill this storage device.
The energy of the fuel reservoir is transformed in mechanical energy by an internal combustion engine. The alternative electrical energy is transformed into mechanical energy by at least one electrical machine.
According to the commands of the driver and the driving conditions of the vehicle, the electrical machine can be used for applying a complementary engine torque to the drive wheels, or for recharging the electrical energy storage devices during braking of the vehicle by applying a braking torque to these drive wheels, or for driving with the electrical machine only without emitting polluting gas.
In this way, the operation of the internal combustion engine can be optimized and the fuel consumption reduced. In particular, it is desirable to stop the internal combustion engine when the vehicle stops, for instance at a traffic light, or during sufficiently low power requirements corresponding with low efficiency of the internal combustion engine. In the last case, the electrical machine is exclusively used for providing traction to the vehicle.
In a variant, hybrid vehicles can comprise another energy source, such as compressed air, replacing electricity for the alternative motor.
In general, these hybrid vehicles include a climate control system for the cabin to cool the ambient air, which comprises a compressor driven by the internal combustion engine, and which produces a cycle of evaporation and liquefaction of a coolant.
One of the problems to be solved is that when the internal combustion engine is not running, the compressor is no longer driven and the vehicle is no longer generating cold for the air conditioning. If the engine shut down persists during warm weather, the ambient temperature of the cabin will rise, which could be uncomfortable.
A known climate control system disclosed in French Pat. No. FR2866831 comprises a cold storage device constituting a cold reserve, which is cooled by circulation of a coolant fluid when the internal combustion engine is running. When the vehicle stops, and the internal combustion engine is not running, the cold storage returns this cold in order to continue to cool the cabin of the vehicle.
If the vehicle stop is prolonged, the cold reserve may run out, requiring the restart of the internal combustion engine strictly to provide a source of cold and to maintain the same level of comfort. Since the operation of an internal combustion engine is not optimized at low power, it results in high specific fuel consumption, which is not favorable for reducing consumption and polluting emissions.